Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Computerized tomography (CT) involves the imaging of the internal structure of a target object by collecting projection image data in a single scan operation (“scan”). CT is widely used in the medical field to view the internal structure of selected portions of the human body. In an ideal imaging system, rays of radiation travel along respective straight-line transmission paths from the radiation source, through a target object, and then to respective pixel detectors of the imaging system to produce accurate projection image data and volume data (e.g., volumetric image) without artifacts.
However, in practice, projection image data may contain errors or inconsistencies that result in artifacts in volume data reconstructed from the projection image data. For example, projection image data acquired using a flat panel detector may be affected by physical characteristics of the flat panel detector, such as due to offset, gain, nonlinearity and lag, etc. All of the foregoing lead to image degradation and affects any subsequent processing or diagnosis and treatment planning. It is therefore desirable to develop techniques for improving image quality of the projection image data to reduce artifacts in the volume data.